As disclosed, for example, in the following patent documents, transesterification reactions are used to produce fatty acid esters, with oils and fats, which are esters of fatty acids and glycerol, serving as starting materials. Caustic soda and other alkali catalysts, as well as zinc catalysts, lipases, and the like are used as the catalysts. It has also been proposed to perform reactions in a supercritical state without adding a catalyst.
Patent document 1 Patent Publication No. 9-235573A
Patent document 2 Patent Publication No. 7-197047A
Patent document 3 Patent Publication No. 2000-143586A